首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2204篇
  免费   92篇
  国内免费   27篇
耳鼻咽喉   49篇
儿科学   41篇
妇产科学   42篇
基础医学   185篇
口腔科学   66篇
临床医学   152篇
内科学   742篇
皮肤病学   8篇
神经病学   120篇
特种医学   74篇
外科学   291篇
综合类   7篇
一般理论   1篇
预防医学   41篇
眼科学   4篇
药学   93篇
中国医学   2篇
肿瘤学   405篇
  2023年   12篇
  2022年   39篇
  2021年   55篇
  2020年   28篇
  2019年   41篇
  2018年   64篇
  2017年   31篇
  2016年   58篇
  2015年   63篇
  2014年   59篇
  2013年   63篇
  2012年   153篇
  2011年   161篇
  2010年   85篇
  2009年   58篇
  2008年   101篇
  2007年   114篇
  2006年   110篇
  2005年   144篇
  2004年   115篇
  2003年   128篇
  2002年   105篇
  2001年   52篇
  2000年   54篇
  1999年   29篇
  1998年   16篇
  1997年   21篇
  1996年   16篇
  1995年   10篇
  1994年   18篇
  1993年   18篇
  1992年   33篇
  1991年   21篇
  1990年   22篇
  1989年   33篇
  1988年   30篇
  1987年   18篇
  1986年   14篇
  1985年   16篇
  1984年   20篇
  1983年   6篇
  1982年   7篇
  1981年   7篇
  1979年   6篇
  1977年   6篇
  1976年   5篇
  1973年   6篇
  1972年   5篇
  1971年   10篇
  1969年   4篇
排序方式: 共有2323条查询结果,搜索用时 15 毫秒
61.

Background

This study was designed to determine the surgical outcomes of gastric cancer in elderly patients. This information can help establish appropriate treatment for these patients.

Methods

A total of 1,193 patients with gastric cancer who underwent gastrectomy between 1995 and 2010 were enrolled in this retrospective study. The clinicopathologic features of 104 elderly patients (aged ≥80 years) were compared with those of 1,089 nonelderly patients.

Results

(1) Tumors located in the lower-third of the stomach, differentiated cancer, and surgery with limited lymph node dissection were more common in elderly patients. However, there was no difference in the proportion of laparoscopic gastrectomy between elderly and nonelderly patients. (2) Although surgical complication rates were similar in the two groups, the operative mortality rate was higher in elderly patients (1.9 %) than in nonelderly patients (0.7 %). (3) Elderly patients had a significantly poorer overall survival rate, whereas the disease-specific survival rates of the two groups were similar. Limited lymph node dissection did not influence the disease-specific survival rate of elderly patients. (4) The median life expectancy of elderly gastric cancer survivors was 9.8 years in patients aged 80–84 years and 6.0 years in those ≥85 years. The patients with limited lymph node dissection had slightly better prognosis.

Conclusions

The treatment results in elderly patients were comparable to those in nonelderly patients. These findings suggest that R0 resection with at least limited lymph node dissection according to Japanese guidelines should be considered, even for elderly patients.  相似文献   
62.
A 56-year-old female was admitted to our hospital because of respiratory symptoms. Her admission ECG showed normal sinus rhythm and standard echocardiographic evaluation showed no structural or functional abnormalities. She was diagnosed as having sarcoidosis by imaging modalities and mediastinum lymph node biopsy. In this case, 2-dimensional speckle-tracking echocardiography (STE) demonstrated abnormal regional myocardial function and delayed enhancement cardiac magnetic resonance imaging revealed a high intensity area in the same segments. This case suggests that STE is potentially useful for the detection of cardiac sarcoidosis in the early phase.  相似文献   
63.
The projection pattern of the olivocerebellar (OC) axons, which terminate mainly as climbing fibers (CFs) in the cerebellar cortex, tightly reflects the compartmental and developmental organization of the cerebellum as revealed by mapping and reconstruction studies in the rat. The avian cerebellum is well lobulated and longitudinally compartmentalized like the mammalian cerebellum. However, the projection pattern of the OC axons has not been studied in detail for most areas of the avian cerebellum. In the present study, we reconstructed labeled chick OC axons resulting from a small focal injection of biotinylated dextran amine into the inferior olive to investigate their morphological characteristics, and to determine their relationship to the general morphology of the chick cerebellum. Labeled CFs were distributed basically in a single longitudinally elongated narrow band‐shaped area in lobules I–VIII, but in multiple, transversely widened, band‐shaped areas in lobules IX–X. Three of the four reconstructed OC axons terminated in a single longitudinally band‐shaped area in lobules IXa–c, whereas the other one terminated in multiple mediolaterally separated areas in lobule IXc, which is part of the flocculus. Single OC axons branched into 14 CFs on average. Two CFs occasionally merged to form a single terminal arbor. Axons also had thin, non‐CF collaterals that projected either to a cerebellar nucleus or to the cortex. The results indicate that the morphological characteristics of OC axons, including branching and termination, are basically conserved between the chick and the rat. J. Comp. Neurol. 521:3321–3339, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   
64.
The purpose of our study was to evaluate the effects of surface modifications on the bond strength between veneering porcelains and Yttria-stabilized tetragonal zirconia (Y-TZP). In a bond strength tests, the effect of control, 70 μm alumina-sandblasting, 30 μm and 110 μm silica-coating of the Y-TZP surface on bonding were evaluated with veneering porcelains. In addition, the effect of surface modification on the flexural strength of Y-TZP was also evaluated. The data was analyzed using one-way ANOVA and Tukey test. All specimens showed bond strength values in excess of 25 MPa, the minimum allowed by ISO9693. In addition, significantly differences were found between the control and the 30 μm silica-coated. On the other hand the flexural strength of Y-TZP does not significantly difference for any surface modification. These results indicate that silica-coating may provide an effective pre-treatment for this enhancement of the bond strength while maintaining the strength of Y-TZP.  相似文献   
65.
66.
Annals of Nuclear Medicine - Somatostatin receptors are highly expressed in neuroendocrine tumors, and many radiolabeled somatostatin analogs for diagnosis and treatment have been developed. To...  相似文献   
67.
Journal of Autism and Developmental Disorders - This study was a systematic review of research using the Wechsler Intelligence Scale for Children (WISC) with Autism Spectrum Disorder (ASD) to...  相似文献   
68.

Purpose

Our aim was to determine whether the maximum standardized uptake value (SUVmax) of the primary lesion demonstrated by [18F]-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is associated with the prognosis of maxillary sinus cancer.

Materials and methods

The relationships of clinicopathological factors including age, T stage, N stage, histologic type, treatment strategy, and primary tumor SUVmax with progression-free (PFS) and overall (OS) survival were evaluated using the log-rank test and Cox method in 31 patients with maxillary sinus cancer before combined superselective intra-arterial chemotherapy using high-dose cisplatin with concurrent radiotherapy, or radiotherapy alone.

Results

The median duration of follow-up was 55.4 (range 9.7–72.6) months. PFS and OS of patients exhibiting a high SUVmax (≥16 and ≥17, respectively) for the primary tumor were significantly lower than those of patients for whom the primary tumor SUVmax was low (p = 0.0010 and p = 0.033, respectively). Multivariate analyses showed that T stage (p = 0.0049) and primary tumor SUVmax (p = 0.026) were independently prognostic of poorer PFS and that only primary tumor SUVmax (p = 0.049) was independently prognostic of poorer OS.

Conclusion

SUVmax of the primary tumor determined by FDG-PET/CT before treatment could be a good surrogate marker for prognostication of maxillary sinus cancer.
  相似文献   
69.
70.

Background and objectives

Hepatic resection is established as the treatment for HCC. However, patients sometimes experience early recurrence of HCC (ER HCC) after curative resection.

Methods

A retrospective analysis was conducted for 193 patients with single HCC who underwent curative liver resection in our medical center between April 2000 and March 2013. We divided the cohort into two groups; early recurrence group (ER G) which experienced recurrence within 6 months after resection, and non-early recurrence group (NER G). Risk factors for ER HCC were analyzed.

Results

Thirty-nine out of 193 (20.2 %) patients had ER HCC. Univariate analysis showed Glasgow prognostic score (GPS, p = 0.036), neutrophil to lymphocyte ratio (NLR, p = 0.001), level of PIVKA-II (p = 0.0001), level of AFP (p = 0.0001), amounts of blood loss (p = 0.001), operating time (p = 0.002), tumor size (p = 0.0001), stage III and IV (p = 0.0001), and microvascular invasions (portal vein: p = 0.0001 and hepatic vein: p = 0.001) to be associated with ER HCC. By multivariate analysis, there were significant differences in high NLR (p = 0.029) and high AFP (p = 0.0001) in patients with ER HCC.

Conclusions

Preoperative high AFP (more than 250 ng/ml) and high NLR (more than 1.829) were independent risk factors for ER HCC.
  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号